I have a publishing system that produces atom feeds based on a complex saved search. The saved search can be fairly unique for each of our users and in reality no 2 users ends up querying the feed system in the same way ie. the url for the feed will almost always be different.
At the moment we have between 10-20k users for these feeds using polling for their updates (we also have a scheduling system which pushes updates behind the scenes for specific clients but this requires a fair amount of config work). Given that it is nigh on impossible for the publisher to tell which feeds should be updated when something new is added, is there anyway Pubsubhubbub could be used in this scenario without reverting to polling each url for an update? Have you encountered this problem before?
